flesh out classpath enough to test threading; fix indexing bug in parsePool()

classpath/java/lang/String.java

@@ -1,8 +1,41 @@
 package java.lang;
 
 public final class String {
-  private byte[] bytes;
+  private Object data;
   private int offset;
   private int length;
   private int hash;
+
+  public int length() {
+    return length;
+  }
+
+  public static String valueOf(int v) {
+    return valueOf((long) v);
+  }
+
+  public native void getChars(int offset, int length,
+                              char[] dst, int dstLength);
+
+  public static String valueOf(long v) {
+    if (v == 0) {
+      return valueOf('0');
+    } else {
+      final int Max = 21;
+      char[] array = new char[Max];
+      int index = Max;
+      long x = (v >= 0 ? v : -v);
+
+      while (x != 0) {
+        array[--index] = (char) ('0' + (x % 10));
+        x /= 10;
+      }
+
+      if (v < 0) {
+        array[--index] = '-';
+      }
+
+      return vm.Strings.wrap(array, index, Max - index);
+    }
+  }
 }